Nudity, or nakedness, is a state of being in which a human is not wearing clothing or is not covering the genitals. In some societies, partial nudity is defined as not covering other parts of the body that are deemed to be sexual.
Nakedness was the natural state of human beings for millennia in tropical climates and continues to be the norm in many isolated indigenous societies in tropical regions during the 21st century. The modern understanding of nudity is culturally complex due to different meanings given various states of undress in differing social situations. In any particular society, nudity is defined in relation to being properly dressed, not in relation to the specific body parts exposed. For humans, nakedness and clothing are connected to many cultural categories such as identity, privacy, social status and moral behavior. Synonyms and euphemisms for nudity abound, including "birthday suit", "in the altogether" and "in the buff". "In a state of nature" is also used by philosophers to refer to the state of humans before the existence of organized societies.
In Western societies, there are two contradictory cultural traditions relating to nudity. The first comes from the ancient Greeks, who saw the naked body as the natural state and as essentially positive. The second is based upon the Abrahamic religions, which have viewed being naked as shameful and essentially negative. The fundamental teachings of Judaism, Christianity, and Islam prohibit public, and sometimes also private nudity. However, the interaction between the Greek classical and later traditions has resulted in Western ambivalence, with nudity representing both positive and negative meanings in individual psychology, in social life, and in depictions such as art. In modern times, organized groups of nudists or naturists have emerged with the stated purpose of regaining a natural connection to the human body and nature, sometimes in private spaces but also in public.